Speciation, Dissolution, and Redox Reactions of Chromium Relevant to Pretreatment and Separation of High-Level Tank Wastes

[摘要] This proposed research builds on the fundamental data developed under former EMSP project (65368) and seeks to develop additional fundamental data for chromium (Cr) reactions that are not currently available but are essential for the processing of high-level waste (HLW). Our objectives are to study (1) the dissolution of several solid phases (e.g., CrOOH, Cr2O3(c), and Fe and Cr, binary hydroxides, identified to be important from sludge leaching studies) in highly alkaline solutions and in the presence of other electrolytes (e.g., carbonate, phosphate, sulfate, nitrite), and (2) the effect of the nature of Cr solid phases and aqueous species on their redox reactivity with a variety of potential oxidants (e.g., O2 and ferrate). This information will provide critical support for developing enhanced pretreatment strategies for removing Cr from HLW and will achieve a major cost reduction in HLW disposal.

[发布日期] 2002-06-01 [发布机构] Pacific Northwest National Lab., Richland, WA

[关键词] Leaching;Sludges;Oxidizers;Hydroxides;Redox Reactions